North Korean soldiers pay tribute to a statue of the late leader Kim Il Sung as they tour a newly constructed Korean War museum in Pyongyang, officially opened on July 27, 2013, to mark the 60th anniversary of the Korean War armistice

On July 27, 1953, an armistice was agreed to bring an end to a bloody three-year war fought between a divided Korean peninsula and the American and communist forces backing either side. Decades later, no peace treaty has been signed. Tourists who visit the demilitarized zone, or DMZ, that separates North and South Korea bear witness to the last frozen battlefield of the Cold War, a conflict that to this day defines and shapes the societies living on either side of the 38th parallel. South Korea has emerged as an economic powerhouse, a global trendsetter whose companies and pop stars are celebrated across continents and whose population is perhaps the world’s most Internet savvy. North Korea, on the other hand, is the least-connected place on earth, a nation built entirely on the propaganda and brutality of its totalitarian, post-Stalinist regime. TIME spoke with Sheila Miyoshi Jager, a professor of East Asian studies at Oberlin College in Ohio and author of the new book Brothers at War: The Unending Conflict in Korea, on how a 20th century war continues to influence 21st century geopolitics in one of the most strategic corners of the planet.

60 years later, what’s the enduring legacy of the Korean War?For the Americans, the Korean War is really viewed as a forgotten war. It’s a war stuck between World War II and Vietnam. And the American memory of it is really confined to that of the American military experience in the three years when the war was fought. But that’s not the way the Koreans experience the conflict. For Koreans, it continues to be a living and breathing event. They’re confronted with it and the enduring effects of the division of the peninsula constantly. So in my book, I wanted to emphasize the unending aspect of the war and to show how it continues to affect the two Koreas and the region. I also wanted Americans to realize how seminal the Korean War was in the history of the 20th century — that because it never ended in a peace treaty, the war continued to influence events well beyond 1953.

How dramatically have the two halves of Korean peninsula changed since its division?The peninsula was divided in 1945 at the 38th parallel by the United States and the Soviet Union. In 1948, North and South Korea were established, and then of course, a war erupted in June 1950 when Kim Il Sung, with Stalin’s backing, launched an invasion of South Korea in an effort to unify the peninsula by force. Now, after the war, actually, North Korea was far ahead of the South economically. But because of the inefficiencies of the Stalinist economic system, the economy eventually began to retract. In some cases, North Korean factories were mass-producing products that were defective, but they continued to produce them anyway to fulfill abstract quotas. So by the late 1960s, the North was already falling behind, whereas the South, which set about instituting an export-oriented economy [under the authoritarian rule of President Park Chung-hee], was forging ahead.

And that’s when the divergence between North and South Korean systems starts to take place, and you begin to see a lot of provocations and incursions by the North: the attempted assassinations of Park Chung-hee and the Pueblo incident in 1968, for example. In fact, between 1967 and 1969, the DMZ was declared a combat zone because of increased military action there. These incursions were really a recognition by Kim Il Sung that the window of opportunity to reunify the country under his rule was closing. And then, of course, the North Korean economy goes into decline through the 1980s and then completely collapses at the end of the Cold War with the fall of the Soviet Union. This was because North Korea had relied extensively on Soviet aid and concessional pricing for trade. By contrast, South Korea is roaring ahead — it hosts the Olympics in 1988, garnering all the prestige that comes with it.

So, in essence, the South has won the argument?Not initially. North and South Korea have always been locked in an ongoing legitimacy struggle. South Korea has defined itself very much against the North, and the North has defined itself in opposition to the South. North Korea imagines that it is the purer and more authentic Korea, in part because the South’s leaders were connected to the Japanese colonial regime. Park Chung-hee was once a Japanese military officer, after all. Plus, of course, in the South, you have the American military presence while in the North, no foreign troops are stationed on its soil. The North thus staked out the territory of true “Koreanness” based on these distinctions, despite their inability to compete economically. But since then, the South’s legitimacy has been bolstered by its economic prestige, as well as its successful turn toward democracy.

And while South Korea is now a noisy democracy, North Korea is still hidebound by the rule of the Kims. Could the state exist without the dynasty?I don’t think North Korea can exist without the Kim dynasty. The very fabric of its identity and sense of being is caught up in the Kim family. Kim Il Sung died in 1994 but is still revered as the Eternal President. Kim Jong Un is where he is today because he is Kim Il Sung’s grandson. When Kim Jong Un was introduced to the public in 2010, he adopted a lot of Kim Il Sung’s persona — his gestures, his hairstyle. He’s styled as a living embodiment of his grandfather. I don’t see North Korea actually existing without the Kim dynasty because the Kim dynasty is North Korea.

So if the Kims were to go, what prospects would there be for a kind of reconciliation and later unification?That depends on what North Korea would look like after the Kim dynasty, and no one can see that far into the future. As it stands now, however, I don’t see the prospect of unification as a reality. How can the North open up to the South without losing control over its own people? The more the North Korean people know about the South, the less likely they are to put up with the conditions of poverty and repression at home. So any reforms that would push North Korea down the same path as the South can’t be accepted because that would mean the end of the regime. North Korea is thus in a catch-22 situation. Pyongyang needs drastic reforms to improve the lots of the North Korean people, but any reforms that would open up the country would lead to the demise of the regime. The way I see the end of the Korean War happening is that China [the North’s sole remaining major ally, which doesn’t want the North to fall into the U.S.’s orbit of influence] would shield North Korea from internal collapse while promoting incremental reforms under its shield. But North Korea cannot open itself up — the more its own people know about the outside world, the more fragile the state becomes.

How does this all play out in the South? Is there much enthusiasm for unification?If you look at internal polls, the interest in unification in the South has drastically waned. In the 1980s, the vast majority was in favor of it, but today, among the younger population, it’s something like 20%. So while the South talks about unification, the reality is that they think it’s going to be way too expensive. And among the younger generation, there’s a sense that they shouldn’t give up anything for the North.

This past spring, when you had all these provocations from the North — threatening to make Seoul a “sea of fire” and so on — what you had in the South was complete indifference. South Koreans were shopping and going about their daily lives, not really paying attention. It was really the Western media that got all hysterical about the North’s blustering. That indifference extends now even to the human-rights situation in the North. North Korean defectors complain that they feel like second-class citizens — they’re not integrated into nor embraced by South Koreans. They know that the legitimacy struggle has ended and the vast majority of South Koreans are not really interested any more. This stands in stark contrast to North Korea, which is constantly fearful of the South. You can be sent to jail for whistling a South Korean tune or listening to a South Korean broadcast. There’s an extreme hypersensitivity to anything about the South in the North.

Sixty years since the armistice, and now one of the Koreas is a nuclear power. How great a threat is the North’s suspected nuclear arsenal?The nuclear program was created by Kim Il Sung as a way for survival in the face of the country’s collapsing economy. It uses its existence as a stick to get more aid from the international community. But that doesn’t mean it would use its weapons or start a new war — it knows a war would mean the end of the regime. And the North Korean leadership is not suicidal.